Demethylation agents could restore the expression of MHC class I and its antigen presentation machinery in cancer cells 36-39, and induce the expression of tumor antigens 40, 41, Some studies also revealed that demethylation treatment could up-regulate the expression of costimulatory molecules, such as CD80, CD83, and CD86 38, 42, 43. This evidence concerns the gene CD83 and cancer.